Lettering film



4, 1953 o. J. DOUGLAS ETAL 2,647,848

LETTERING-FILMS Filed April 10, 1950 |0""" [NVENTORS DONALD J. DOUGLAS\j PHIL/P 1/. ALM u/sr J5 ROME D. 6/20 v5 A TTO/ENEYS Patented Aug. 4,1953 UNITED STATES PATENT OFFICE LETTERING FILM Application April 10,1950, Serial No. 155,101

11 Claims.

This invention relates to lettering-films and to the application of suchfilms, in the form of letters, designs and the like, to bare metal andother surfaces. The products of the invention have found particularutility in providing lettering and insignia for the bare metal exteriorsurfaces of airplanes and for the beaded surfaces of reflex-reflectiveroadside signs.

Of the previously available means for providing letters and insignia onmetal and other surfaces, hand painting and stenciling are perhaps thebest known. On metal, the process ordinarily involves extensivepreliminary preparation of the surface, including cleaning and priming,followed by application and drying of the paint. The process istime-consuming, particularly since it must be frequently repeated. Onglass-beaded reflexreflective signs, hand lettering has been the generalrule. The time required for drying of the paint, added to the timerequired by the artist, makes this procedure slow and costly,particularly since the available paints do not hold up as long as thebeaded surface, but must be replaced at least once during the usefuloutdoor life of the sign.

A particular shortcoming of hand painting methods is that many of themost weather-resistant coating materials do not lend themselves to suchsystems of application. Some of these materials form extremely viscousand stringy solutions at all useful concentrations. Others requirespecial solvents which must be used under rigidly controlled conditions.Still other materials attain their full weather-resisting qualities onlyafter being heat-treated at high temperatures. In most cases, some sortof priming orundercoating is required, since the most resistant coatingmaterials do not readily adhere to metal, glass, or other surfaces.

One way which has previously been suggested for the rapid application ofletters and insignia to various surfaces is by means of printedtransfers or decalcomanias. One advantage of such procedure is that theprinted material may be produced economically and with exact uniformityfrom sample to sample. These decals are ordinarily in the form ofextremely thin printed films bonded to an overlapping carrier web, fromwhich they are removable on moistening with water or other appropriatesolvent. The thin film is then either floated" on to the work-surface,where it adheres by virtue of a soluble adhesive component, or isdirectly transferred to the work-piece after either the work-piece orthe printed film is first coated with a thin layer of adhesive. Varnishis commonly employed in the latter case as the adhesive material. Itforms a fully acceptable bond to many painted surfaces; however it doesnot adhere Well to glass or bare metal. Water-soluble adhesives areundesirable for outdoor application where prolonged weather-resistanceis a requirement. Where a liquid adhesive is applied to thework-surface, such as a beaded sign, it invariably extends past theboundaries of the subsequently applied decal film, and thus interfereswith reflex-reflection of the underlying beaded surfaces. Large areas,long stripes and the like are not conveniently applied by these priorart methods.

Decalcomanias are customarily prepared by screen-processing, or bydirect printing, and these methods are no more applicable to many of themost desirable coating materials than is hand painting.

For these and other reasons, prior art preformed lettering films anddecals have not been found satisfactory for such applications as thelettering of reflex-reflective beaded signs, striping of automobilebodies, and the marking of bare,

or sections of the film to bare metal, beaded.

signs, and other work-surfaces to provide weatli er-resistant,abrasion-resistant, long-wearing, firmly bonded letters and otherinsignia.

cannot be obtained by painting procedures since, in accordance, with thepresent invention, they are formed of non-paintable polymer materialwhich makes possible the obtaining of the desired properties A relatedobject is to provide The thus applied letters, etc., have a durabilitythat a flexible and conformable lettering-film consisting of aweather-resistant decorative layer and a strong and highly adherentadhesive layer, supported on a temporary carrier web in position fordirect application to the work-surface. A further object is theprovision of such composite lettering-films in roll or stack form. thefilm and carrier web being of such nature that the stack may be stamped,sawed, or otherwise formed to provide a large number of letters: orinsignia, and such that the individual letters or insignia, togetherwith their individual lightly adherent carrier webs, may then beseparated from the stack. The film is of a kind that can be directlyapplied to the work-surface to become firmly bonded thereto, and thecarrier web can be removed without moistening or other treatment. I

Still another object is the provision of a supported compositelettering-filmhavinga decorative, highly weather-resistant formed of afilm-forming polymer which in usefully concentrated olution isnon-paintable by the ordinary methods of brushing and; screenprocessing.

By a non-paintable solution is meant a liquid which cannot be applied ina single application by brushing, spraying or. screen-processing toclean metal or wood surfaces to form on drying (without heat-treating) apermanently adherent, uniform, smooth-surfaced, durable andweatherresistant dried coating at least about one mil thick. Liquidswhich string. out badly and leave permanent ridges and irregularities onthe surface of the coating are considered non-pai.ntable. Liquids whichare so dilute that they require multiple applications to provide aone-mil dried coating are likewise considered non-paintable. Liquidswhose air-dried films are easily peeled away from clean paintablesurfaces on which formed are non-paintable. Ina general sense, to bepaintable a solution must have properties of film formation, flow-out,adhesion to clean work-surfaces, and permanence on airdrying, closelyanalogous to those of oil or varnish base paints and enamels. We havefound that most, if not all, of the more weather-resistant film-formingpolymers, in solution form, are non-paintable by such definition, andthese materials are not used by sign-painters;

The present invention accomplishes the above and other objects byproviding a: productwhich will be more fully described later by means ofa number of specific examples, and which is illustrated in theaccompanying. drawing, in which Figure 1 is a view in perspective apre-cut stack of letters,

Figure 2 is a section taken at 2-of Figure 1 showing adjacent portionsof two layers of the stack of letters of Figure l but on an enlargedscale, and

Figure 3 i a sectional representation of a portion of the lettering filmapplied to a reflex-reflective beaded surface.

The construction of the lettering-film is represented in Figure 2, whichshows in cross-section two consecutive layers of the film with attendanttemporary carrier web as taken from the stack 28 of Figure l. Thelettering-film it consists of a decorative weather-resistant andabrasion-resistant protective film layer l2 and non-tacky, heat orsolvent activatible, water-proof, adhesive layer II. Theweather-resistant layer is lightly adhered to one surface l lof thecarrier web l3, the opposite surface [5- of which contacts the surfacelayer 4 adhesive layer I la of the next adjacent letteringfilm Eta inthe stack.

The application of the film to a reflex-reflective beaded surface [6 isshown in Figure 3. In removing a ingle letter from the stack 23,separation occurs between the surface l5 of the carrier web l3 and theadhesive surface I la of lettering-film Illa. At the same time the filmIt remains attached to its carrier i3, and film 19a to its carrier [3a.The detachedsection, consisting of thefilm i0. and carrier i3, is thenplaced on the beaded surface with the adhesive layer M- contacting suchsurface, and i heated and pressed into full adhesive contact therewith.

The film I0 is necessarily flexible and easily deformable in order toconform to the beaded surface l6, andiif handled separately in the formof cut-out letters would be easily pulled out of shape and. would bedifficult if not impossible to position accurately on the work-surface.The weather-resistant layer is, in some cases, somewhat tacky whenheated, and has a tendency to adhere to many surfaces; such adhesion isavoided by thepresence of the treated carrier web. Hence it isdesirable, particularly where heat-activation is to be. employed, thatthe lettering-film remain attached to the carrier until after it ibonded- The same relationships are generally true where the adhesive issolvent-activated. In some cases, however, as where the film is tobeapplied asa long stripe along a curved line or in. a larger area over awork-surface having compound curves, the activating solvent is appliedto the film while. in place on the carrier, and thefilm is then at leastpartially stripped from the car rier before applicationtothe-work-piece.

Where the lettering-film, with itsattendant.

carrier web, is woundup in roll form, it will beapparent that the samegeneral relationships between adjacent layers still apply. In such case,however, since the film and carrier remain as continuous webs in theroll and during unwind,- ing, there is less likelihood-of the temporarybond between film surface !2 and carrier surface it being broken, andhence the adhesion between adhesive surface Ha and carrier surfacel-5-may safely be somewhat higherv thanv in the case of stacks ofpre-cut letters as in Figure-1,

The adhesive relationship between the various surfaces within the stack20 of Figure 1 is-critical to the successful removalof individual unitsfrom the stack and the subsequent successful removal of the carrier webfrom the-individual letter orother segment before orafter bonding tothework-surface. Over-all adhesion must be sufficient to keep theindividual units, together in the stack both before, during and afterstamping or cutting into, a specific desired shape. The bond betweenadjacent units of, the structure must be, and remain, low enough so.that the.

individual units may be separated from the stackwithout. disturbing. therelationshipv between. the.

film and carrier web components of such units, and without delaminatingor otherwise interfering with either component. The bond between.

the two component portionsof each unit must,.on

the other hand, be sufficiently high toovercome:

the pull applied in separating the adjacent units, but must be readilybroken when it becomes necessary to strip the carrier web from thedecorative film, again without delamination or disruption of the film orcarrier.v

These several qualifications are attained, and the several objects ofthe invention accomplished, by means which will now be described interms of specific but non-limitative examples.

EzrampZeI The carrier web consists of heavy flat paper,

for example having a ream weight of 70 lbs. The paper is coated or sizedon one side (the 'face side of the finished web, corresponding to thesurface M of Figure 2) with a plasticized heat-advancing amino-aldehyderesin face-size, and on the back side (surface E5 of Figure 2) with apolyethylene resin back-size. Heating of the coated web cures theamino-aldehyde resin and fuses the polyethylene resin into a continuouslayer.

The face-size comprises an amino-aldehyde resin solution which isprepared as follows, all parts being by weight unless otherwisespecified. To 1000 parts of 37% formaldehyde solution, add concentratedammonium hydroxide to a pl-I of 7-8. Add 240 parts of urea, and heat themixture in a suitable kettle at 85 C. for -55 minutes or until the ureais all dissolved. Apply a vacuum and drop the temperature to -60 C., andthen add 592 parts of n-butyl alcohol, parts petroleum xylol (or xylol)and 6 parts of orthophosphoric acid. Continue heating and distillingunder vacuum, removing the water but returning the organic solvent tothe batch. When no more water comes over, cautiously distill out aportion of the solvent, to produce a viscous, clear solution containingabout 53% by weight of residual solids as determined by heating aweighed 2-3 gram sample in an open dish at an oven temperature of C. fortwo hours and weighing the residue. This solution is diluted withn-butyl alcohol to 50% solids content for use. Beetle Resin 227-8 is acommercially available example of such a resin solution, containing 50%of a urea-formaldehyde-butyI alcohol resin in a mixture of three partsof butanol and two parts of Xylol. For best results these resins shouldhave a turbidity value of about 93-98, where turbidity value is thepercentage of xylol in a solution brought just to turbidity at 25 C. byadding further xylol to a solution of 10 grams of the 50% resin solutionin 75 ml. of xylol.

One part of castor oil is "added to two parts of the resin solutiondescribed above, and, shortly before coating, 60 ml. of a 50% solutionin butyl alcohol of an acid 'alkyl ester of phosphoric acid is added toeach 5 gallons of solution as a catalyst.

The solution is applied to the paper at a wet weight of about 10-13grains per 25 sq. in., and dried for 10-15 minutes in an oven heated toabout 275 F.

The backsize is next applied, and consists of about 6-15 grains per 24sq. in. of a solution of one part polyethylene resin in two parts ofxylol. The coated web is thenheated for about 5 minutes in an oven at300" E, which completes the cure of the face coat and fuses the backcoat into a continuous structure.

In each case, some of the solution penetrates and 'impregnates thepaper, but suiiicientsolution remains on the surface to provide apsmoothglossy finish.

The lettering-film is cast from solution directly on to the face side ofthe carrier web, and in two layers.

The first layer, which becomes the decorative weather-resistant surfacefilm exposed to view in the completed lettered sign, is a pigmentedn-butyl methacrylate polymer. The solution is prepared by millingcarbon-black pigment into the polymer on a rubber mill, separatelydissolving the mill base master-batch and additional polymer in xylol,and combining the two solutions on a paint .mill in the proportions of97.5 parts total polymer and 2.5 parts pigment. About 20- 24 grains per24 sq. in of a solution containing 4.5% solids is applied, by means of aspreader bar, in a uniform smooth layer over the face side of thecarrier web and dried at moderate tem-, peratures, to provide adecorative layer about one to two mils thick. In general, the thicknessof this decorative layer should be at least about one mil, andpreferably at least about 1 mils, in order that the lettering-film willnot be perforated and torn when pressed on to glass beaded or otherirregular surfaces.

The methacrylate polymer solution is viscous and stringy. When spreadwith a brush, it strings badly, leaving a rough anduneven surface whichdoes not flow out on standing, The dried film does not adhere well tosuch surfaces as wood, clean metal, glass, or painted wood, but may bepeeled away with very little effort. Such a polymer is therefore, insolution form, considered to be non-paintable. However the polymer isvery much more resist-ant to weathering and abrasion than such paintablematerials as oil paints, varnish base enamels and nitrocelluloselacquers. For example, a beaded reflexreflective outdoor sign letteredwith the composite lettering-film here described was still in excellentcondition after four years, whereas a similar sign lettered with a highquality black ename1 required re-lettering after only two years. Again,a portion of the lettering-film adhered to a metal panel was stillglossy after one pass with a sand blast, and was only slightly roughenedafter 36 passes, whereas a conventionally applied finish consisting ofone prime coat and two surface coats'of baked alkyd resin enamel on ametal panel was completely removed in less than 36 passes, badlypenetrated in 1'0 passes, and nonglossy after only one pass 01' the sandblast.

The final layer'consists of the heat or solvent activatible adhesive.The solution employed consists of 100 parts of rubberybutadiene-a-crylonitrile copolymer, 10 parts of zinc oxide, 50 partsVinsol. Ester Gum (glycerol ester of gasolineinsoluble resinous extractof pine wood), 50 parts heat-advancing 100% phenol-formaldehyde resincompatible with the copolymer, and 7.8 parts of dibutyl phthalate, in400 parts methyl ethyl ketone. About 30-34 grains per 24 sq. in. of thissolution is applied over the dried n-butyl methacrylate film, and driedat moderate temperatures. The resulting surface is temporarily activatedat F. to a condition in which it aggressively adheres under pressure tometal, glass, and other surfaces. The total thickness of the two layersis about 3-4 mils.

The composite product may then be wound into rolls or cut into sheetsand arranged in stacks, and is ready for use. The stacked sheets maysimultaneously becut into units representnalc te js r th i si n a b u hafiew na aermse- 7. or in other ways. The individual units remaintogether in the stack under ordinary handling, but may be easily removedwhen required. 'During removal, the film remains attached to the treatedface side of the carrier web, with the adhesive surface exposed andready for activation and application to a work-surface. The film may befirmly and permanently bonded to bare metal surfaces, reflex-reflectivebeaded surfaces, painted or lacquered surfaces, etc. by pressingthereagainst at a pressure of not more than about -l5 lbs. per sq. in.and at a temperature of about 200 F. The carrier web is then readilystripped from the film, preferably by a sharp jerking motion, leavingthe glossy black decorative letter in firmly bonded position on theworksurface.

As an alternative means of bonding the film, the adhesive surface may beactivated by lightly moistening with a slow-drying solvent such ascyclohexanone, and by then pressing the activated' film in place andremoving the carrierweb. The solvent gradually escapes, and the filmremains firmly bonded. For this method, the presence of the carrier webduring brush or swab application of the solvent is particularlydesirable.

Bonded to the lean but unprimed bare metal exterior surface of anairplane, such films show remarkable weather-resistance and abrasionresistance, remaining well bonded and attractive in appearance longafter conventional painted areas have deteriorated.

Example 2 This example employs a different face size coating for thecarrier web but is otherwise identical with Example 1.

The face size solution consists of a mixture of 27.3 parts of a 55%solution of an amino-aldehyde-alcohol resin and 142 parts of a 60%solution in a volatile aliphatic hydrocarbon solvent of adrying-oil-modified, glycerol phthalate alkyd resin. Theamino-aldehyde-alcohol resin was prepared from melamine, formaldehydeand butyl alcohol by methods substantially identical to those used forthe urea-aldehyde-alcohol resin of Example 1. An organic acid phosphatewas employed as the catalyst in the solution as applied.

Erample 3 In place of the alkyd resin of Example 2, a slower curingheat-setting oil-modified alkyd resin was used, in this case With theurea-formaldehyde-butanol resin of Example 1, in providing the face sizecoating of the carrier Web. The proportions were 128.6 parts of a 70%solution of the alkyd resin and parts of a 50% solution of.

the amino-aldehyde-alcohol resin.

Example 4 Ethyl methacrylate polymer was substituted for the n-butylmethacrylate polymer film of the previous examples, with any of a widevariety of pigments being added to provide appropriate color andopacity. Thus, white films were made with titanium dioxide pigment;cadmium selenide and toluidine red pigments provided red films. Theparticular pigment employed was not observed to have any eifect on theoperation of the film. The film is improved when about one-fifth of theethyl methacrylate polymer is replaced by n-butyl methacrylate polymer.

Mixtures of equal parts of normal butyl methacrylate and isobutylmethacrylate polymers, copolymers of equal parts of n-butyl and isobutylmethacrylates, copolymers of methyl methacrylate and Z-ethylbutylacrylate, and other mixtures and copolymers having similar hardnessvalues, non-tacky characteristics, etc., have also been substituted forthe methacrylate polymer'of Examples l--3.

As with the specific methacrylate polymer of Example 1, these severalpolymers, copolymers, and mixtures of polymers form non-paintablesolutions and cannot effectively be applied by conventional means.However, the polymers are particularly appropriate for use in our novellettering-film structure, for several reasons. They are outstandinglyweather-resistant and abrasion resistant, and retain their smooth,glossy appearance after years of outside exposure. They are alsoresistant to the solvents employed in the adhesive coating, and do notswell or wrinkle when the adhesive solution is applied duringpreparation of the supported composite film product.

Example 5 While the specific adhesive described in Example 1 is found togive superior results over a wide range of conditions and is muchpreferred, nevertheless other adhesive compositions have given goodresults in a number of' applications.Adhesivesbasedonrubberybutadiene-acrylonitrile polymers and onpolychloroprene rubber, in combination with compatible reactivephenolaldehyde resin, and on butadiene-styrene rubbery polymers as wellas crude rubber in combination with oil-soluble heat-advancingphenolaldehyde resins, have been so used. One specific example consistsessentially of a blend of parts of polychloroprene, 75 parts ofheat-advancing 106% phenol-formaldehyde resin, and 25 parts of hardcoumarone-indene resin, applied from solution in 350 parts of toluol.

Polyethylene has been used on the carrier web as both face size and backsize, in place of the carrier-web structure of Example 1. Films ofpolyethylene have also been used as the carrier web. In such cases, itis believed that the required differential in adherency. within thestack of sheets is obtained because of the fact that the decorativefilm. layer I2 is applied to the carrier web from solution, while theadhesive layer H is. pre-dried before it contacts the carrier web.

Cellophane films may be used as carrier webs where theback side of thefilm is coated with a suitable low-adhesion backsize, thesolventdeposited methacrylate films in particular being lightlyadherent. to, but readily removed from, the cellophane surface. Oneadvantage of such a construction is the extremely smooth, polishedsurface obtained on the lettering-film.

Example 6 In this example, a copolymer of equal parts of n-butyl andisobutyl methacrylates was used as the face-size, and polyethylene asthe backsize, of the carrier web. The decorative film was constituted ofa pigmented heat-curing mixture of alkyd and amino-aldehyde resins, 1.8mils thick, cured for one hour at 200 F. An adhesive film as in Example1 completed the structure.

The alkyd resin was a condensation product of phthalic anhydride 35percent, castor oil fatty acids 45 percent, and glycerine, reacted to anacid number of 4-6, and analyzing 64-66 percent solids in xylol. Theamino-aldehyde'resin 9 was a condensation product of melamine,formaldehyde and butyl alcohol, dissolved in a mixture of butyl alcoholand Xylol to a solids content of 55 percent. The two resin solutionswere mixed in the ratio of 80:20, with 47 parts of bronze pigment beingadded.

When completely dry, the lettering-film remained on the carrier web whentaken from the roll or stack, but the carrier could be easily strippedaway when necessary. The decorative surface was smooth and lustrous.When the same composition was spread in a film and airdried, it did notharden sufficiently, and the surface Was dull in appearance.

Example 7 The carrier web of Example 1 was first coated on the face sidewith a solution of three parts of a vinyl chloride polymer resin and2.33 parts of bronze pigment in 17 parts of eyclohexanone, and the filmcured for minutes at 150 F. The film was 1.4 mils thick. It was thencoated with adhesive as in Example 6.

The vinyl chloride polymer was a product of the copolymerization ofabout 95 parts of vinyl chloride and 5 parts of diethyl fumarate. It issoluble in strong solvents, e. g. cyclohexanone, only to the extentindicated, and produces a viscous solution which can be spread with aknife in a thick layer but which is non-paintable by brushing, spraying,or screen-processing methods.

Having described various embodiments of our invention for purposes ofillustration, but without intent to be limited thereto, what we claim isas follows:

1. A composite supported lettering-film structure as herein described,adapted for storing and for forming into desired shapes while in stackform, with subsequent ready removal 01" individual units therefrom, saidstructure comprising a thin, flexible and conformable lettering-filmtemporarily mounted on a unitary carrier sheet, the lettering-filmconsisting of (l) a decorative weather-resistant film, at least one milthick, of non-paintable organic polymer material selected from the classconsisting of methacrylate polymers vinyl chloride polymers, and aheat-cured blend of alkyd resin and aminoaldehyde resin; and.permanently bonded to one surface of said film, (2) a layer of normallynontacky waterproof adhesive selected from the class consisting ofheat-activatible and solventactivatible adhesives and comprising arubbery polymeric base, a compatible heat-advancing phenol-aldehyderesin, and a compatible thermoplastic tackifier resin; the carrier sheetbeing temporarily adhered to the other surface of said decorative filmand dry-strippable therefrom; said carrier sheet comprising a flexiblesheet material each surface of which constitutes a smooth continuousfilm of a polymer selected from the class consisting of thermosetplasticized amino-aldehyde resin, polyethylene, cellulosic polymer, andmethacrylate polymer; the elements of the structure being selected suchthat the adhesion at normal temperatures of the decorative film to theadjacent surface of the carrier sheet is greater than the adhesion ofthe adhesive layer to the opposite surface of the carrier sheet.

2. Article of claim 1 in which the surface of the carrier sheet oppositethe surface temporarily adhered to the decorative constitutes acontinuous film of polyethylene.

3. Article'of claim 1 in which the decorative film is formed ofnon-paintable material con sisting of a methacrylate polymer.

4. Article of. claim 3 in which the adhesive layer comprises a blend ofrubbery butadieneacrylonitrile polymer and tackifier resins including acompatible heat-advancing phenol-formaldehyde resin, said adhesive beingtemporarily aggressively tacky at ISO-200 F.

5. Article of claim 1' wherein: the decorative= film is formed ofnon-paintable methacrylate polymer; the adhesive layer, is temporarilyag.-.

gressively'tackyat 180-200" F. and comprises a blend .of rubberybutadiene-acrylonitrile polymer and 'ta'ckifier resins including acompatible heat-advancing 100% phenol-formaldehyde resin; the surface ofthe carrier sheet temporarily adhered to the decorative film constitutesa continuous film of a thermoset plasticized aminoaldehyde resin; andthe opposite surface of the carrier sheet constitutes a continuous filmof polyethylene.

6. An article having a surface and, firmly adherently bonded thereto, adecorative and highly weather-resistant lettering-film as defined inclaim 1.

7. An article having a. beaded reflex-reflective surface at leastpartially covered and made nonreflex-reflective by an adherently bondedlettering-film as defined in claim 1.

8. An article having a smooth bare metal surface at least partiallycovered by an adherently bonded lettering-film as defined in claim 1.

9. An article having a painted surface at least partially covered by anadherently bonded lettering-film as defined in claim 1.

10. A plurality of the composite supported lettering-film structuremembers of claim 1 in stack form, the adhesive layer of each interiorlettering-film of said stack being adhered to the adjacent surface ofthe carrier sheet of the adjoining member with an adhesion valuesuflicient to maintain the members removably in stack form, but lessthan the adhesion value between the decorative film and the adjacentsurface of its carrier sheet.

11. A unitary package of lettering-film having a plurality of juxtaposedcomposite layers lightly and removably adherently bonded together, eachof said composite layers consisting of a thin, flexible and conformablecontinuous letteringfllm temporarily mounted on, and substantiallycoterminous with, a flexible carrier sheet; said lettering-filmcomprising (1) a decorative weather-resistant film, at least one milthick, of non-paintable organic polymer material selected from the classconsisting of methacrylate polymers, vinyl chloride polymers, and aheatcured blend of alkyd resin and amino-aldehyde resin; and,permanently bonded to one surface of said film, (2) a layer of normallynon-tacky waterproof adhesive selected from the class consisting ofheat-activatible and solvent-activatible adhesives and comprising arubbery polymeric base and a compatible heat-advancing phenolaldehyderesin; said carrier sheet being temporarily adhered to the other surfaceof said decorative film and dry-strippable therefrom, and comprising aflexible sheet material each surface of which constitutes a smoothcontinuous film of a flexible waterproof film-forming polymer selectedfrom the class consisting of thermoset plasticized amino-aldehyde resin,polyethylene, 'cellulosic polymer, and methacrylate polymer; and saidunitary package being 11 12 further characterized in that the adhesivebond References Cited in the file of this patent at normal36111119612111.1165 between the decorative 'UNITED STATES PATENTS filmand the ad acent surface of the carrier sheet within one said compositelayer of said package Number Name Date is greater than the bond betweenthe adhesive 5 2,275,957 101 1942 layer and the opposing surface of thecarrier 2,353,717 FranmsFt a1 July 1944 sheet of the next adjacentcomposite layer of 2,383,884 Palmqulst 1945 said package, to a degreepermitting removal of 2394301 Lajws 12, 1946 the outermost of saidcomposite layers from said 21558304 Wlttgren July 1951 package. withoutdisruption of the temporary 10 bond between the carrier-sheet and. theweatherresistant. .film of said outermost composite layer.

DONALD J. DOUGLAS. PHILIP V. PALMQUIST;

JEROME D. GROVE. 15 i

1. A COMPOSITE SUPPORTED LETTERING-FILM STRUCTURE AS HEREIN DESCRIBED,ADAPTED FOR STORING AND FOR FORMING INTO DESIRED SHAPES WHILE IN STACKFORM, WITH SUBSEQUENT READY REMOVAL OF INDIVIDUAL UNITS THEREFROM, SAIDSTRUCTURE COMPRISING A THIN, FLEXIBLE AND CONFORMABLE LETTERING-FILMTEMPORARILY MOUNTED ON A UNITARY CARRIER SHEET, THE LETTERING-FILMCONSISTING OF (1) A DECORATIVE WEATHER-RESISTANT FILM, AT LEAST ONE MILTHICK, OF "NON-PAINTABLE" ORGANIC POLYMER MATERIAL SELECTED FROM THECLASS CONSISTING OF METHACRYLATE POLYMERS VINYL CHLORIDE POLYMERS, AND AHEAT-CURED BLEND OF ALKYLD RESIN AND AMINOALDEHYDE RESIN; AND,PERMANENTLY BONDED TO ONE SURFACE OF SAID FILM, (2) A LAYER OF NORMALLYNONTACKY WATERPROOF ADHESIVE SELECTED FROM THE CLASS CONSISTING OFHEAT-ACTIVATIBLE AND SOLVENTACTIVATIBLE ADHESIVES AND COMPRISING ARUBBERY POLYMERIC BASE, A COMPATIBLE HEAT-ADVANCING PHENOL-ALDEHYDERESIN, AND A COMPATIBLE THERMOPLASTIC TACKIFIER RESIN; THE CARRIER SHEETBEING TEMPORARILY ADHERED TO THE OTHER SURFACE OF SAID DECORATIVE FILMAND DRY-STRIPPABLE THEREFORM; SAID CARRIER SHEET COMPRISING A FLEXIBLESHEET MATERIAL EACH SURFACE OF WHICH CONSTITUTES A SMOOTH CONTINUOUSFILM OF A POLYMER SELECTED FROM THE CLASS CONSISTING OF THERMOSETPLASTICIZED AMINO-ALDEHYDE RESIN, POLYETHYLENE, CELLULOSIC POLYMER, ANDMETHACRYLATE POLYMER; THE ELEMENTS OF THE STRUCTURE BEING SELECTED SUCHTHAT THE ADHESION AT NORMAL TEMPERATURES OF THE DECORATIVE FILM TO THEADJACENT SURFACE OF THE CARRIER SHEET IS GREATER THAN THE ADHESION OFTHE ADHESIVE LAYER TO THE OPPOSITE SURFACE OF THE CARRIER SHEET.